Numbers 9:2-3 “..perform the Passover at its appointed time ..According to all its laws and right-rulings you perform it.”
:6 “But there were men who were defiled for a being of a man, so that they were not able to perform the Passover on that day.”
:8 “Wait, let me hear what YHWH commands concerning you.”

Verse 10-14 explains that if anyone cannot perform the Passover at the appointed time, he is given another way. But if anyone can perform the Passover but doesn’t keep it, then they will bear the sin and be cut off.

What it comes down to, is two things

1.  do you know the instructions?
2. what is in your heart?

In 2 Chronicles 30 we have the story of Israel that has not performed Passover for years, and King Hezekiah rededicates the Temple and calls on Israel to start keeping the Torah/Law again. Everything happened really fast and it was right at the time of Passover. Peoples’ hearts were moved and they really wanted to return back to the path of YHWH. The people didn’t perform the Passover exactly as the YHWH commanded according to the His Laws.

2 Chron 30:18-20 “yet they ate the Passover contrary to what was written. But Hezekiah prayed for them, saying, “YHWH who is good, provide atonement for everyone who has prepared his heart to seek Elohim, YHWH Elohim of his fathers, though he is not cleansed according to the cleansing of the set-apart place.” And YHWH listened to Hezekiah and healed the people.”

(1) They learned the truth, (2) In their heart they wanted to follow the truth, so YHWH healed them.

The word healed in Hebrew is RAPHA H7495 – rāp̄ā‘, which means to restore. Today we do not have a Temple, Tabernacle, Altar, Priests.. but still we really want to KEEP His Torah and His Appointments – after all YHWH commanded it is forever. He never said it is only for some people, for a specific time – He said “forever” – Exodus 12:14 “observe it as a festival, an everlasting law.” We lack the exact knowledge and the means to do it perfectly, but we can just pray this prayer of King Hezekiah “YHWH who is good, provide atonement for everyone who has prepared his heart to seek Elohim“

• Hosea 14 “return to YHWH your Elohim, for you have stumbled by your crookedness…Take away all crookedness, and accept what is good, and we render the bulls (sacrifice) of our lips.. (YHWH says: ) I shall heal their backsliding, I shall love them spontaneously.. Those who dwell under His shadow shall return. They shall revive like grain, and blossom like the vine, and become as fragrant as the wine of Lebanon. Who is wise and understands these words, discerning and knows them? For the ways of YHWH are straight, and the righteous walk in them, but the transgressors stumble in them.”
• Psalm 30:2 O YHWH my Elohim, I cried unto thee, and thou hast healed H7495 me.
• Psalm 41:4 I said, YHWH, be merciful unto me: heal H7495 my soul; for I have sinned against thee.
• James 4:17 To him, then, who knows to do good and does not do it, to him it is sin.
• 2 Peter 2: 21 For it would have been better for them not to have known the way of righteousness, than having known it, to turn from the set-apart command delivered unto them. (new testament)